The Russian presidential human rights council has presented Vladimir Putin with its proposal for a sweeping prison amnesty to mark the 20th anniversary of the country's adoption of its post-Soviet constitution. Up to one-quarter of the country's inmates could walk free under the amnesty.

Who initiated the planned amnesty?

Russian President Vladimir Putin tasked his human rights council in September with drawing up a proposal for a prison amnesty. On October 15, which was the deadline given by Putin, the human rights council submitted its suggestions.

The proposal now needs to be reviewed by the State Duma, which is responsible for enacting the amnesty. The amnesty marks 20 years since Russia adopted its current constitution, on December 12, 1993, following the collapse of the Soviet Union.

Who is eligible for release under the proposal?

The head of the presidential human rights council, Mikhail Fedotov, has described the amnesty as "broad."

Unlike a pardon, which addresses individual cases, an amnesty lists categories of inmates eligible for release. The proposed amnesty also applies to people currently being prosecuted by lifting the charges against them and closing their case.

People serving a sentence of up to three years for nonviolent crimes fall under the amnesty, provided that this is the first time they were convicted. For crimes caused by negligence, people jailed for up to five years are eligible. War veterans, elderly people, pregnant women, women with underage children, people with disabilities, and the terminally ill also fall under the amnesty.

In addition, the council suggests freeing people sentenced for taking part in demonstrations as long as they did not seriously harm anyone or cause significant material damage. It also includes militants, including radicals in the North Caucasus, who have laid down their weapons -- provided they are not serving time for acts of violence.

People convicted of murder, abduction, torture, rape, human trafficking, and other violent crimes are excluded from the amnesty. So are repeat offenders deemed dangerous and individuals who have already been amnestied or pardoned in the past.

According to human rights council member Kirill Kabanov, one-quarter of all inmates held in Russian jails could be released if the proposal is adopted by parliament. This would make it the largest amnesty so far in post-Soviet Russia.

Could high-profile inmates such as former oil executive Mikhail Khodorkovsky or Pussy Riot members Nadezhda Tolokonnikova and Maria Alyokhina walk free?

Particular attention has been paid to whether the amnesty will extend to inmates regarded by human rights groups as political prisoners.

Tolokonnikova and Alyokhina, the members of the Pussy Riot punk collective sentenced to two years in prison for staging an anti-Kremlin performance in a Moscow cathedral, technically fall under the proposed amnesty. Both have young children.

Fedotov says anticorruption campaigner and opposition leader Aleksei Navalny, who was handed a five-year suspended prison sentence this week on embezzlement charges, could also be eligible.

Observers are divided over whether Mikhail Khodorkovsky and Platon Lebedev could be released. Each was convicted twice for alleged fraud and tax evasion, suggesting they don't fall under the amnesty. But since their jail terms have run consecutively, neither can be considered recidivists.

Only three of the 25 defendants in the so-called Bolotnaya case, who were charged with participating in mass riots after attending an opposition rally in Moscow last year, could immediately benefit from the amnesty.

Charges could be dropped against Maria Baronova, who is barred from leaving Moscow, since she has a 6-year-old son. The 50-year-old Yelena Kokhtareva, who is barred from leaving Moscow for the duration of her investigation and trial, could also be spared due to her age. So could Konstantin Lebedev, who has already been sentenced to 30 months in prison in the case.

Mikhail Kosenko, who was declared mentally incompetent and sentenced to a psychiatric clinic by a court last week, does not fall under the amnesty since the ruling formally clears him.

Other defendants in the Bolotnaya case could potentially be amnestied if their prison sentences do not exceed three years, although the charges they face carry sentences of up to 10 years in prison.

Putin, however, has said he does not rule out an amnesty for the Bolotnaya defendants.

As for the 28 environmental activists and two journalists detained last month in the Arctic onboard a Greenpeace ship, their chances of being amnestied appear slim. The piracy charges they face exclude them from qualifying for the proposed amnesty, the newspaper "Novaya gazeta" reports.

What are the benefits for Russia?

First, a sweeping amnesty would allow Russia to ease its critically overcrowded jails.

Second, Putin has come under fire for what critics describe as a crackdown on dissent since he returned to the Kremlin last year for a third presidential term.

A vast prison amnesty could help him soothe detractors and counter accusations that he has used the courts to sideline opponents.

Some, like opposition figure Boris Nemtsov, believe the amnesty also aims at persuading foreign leaders and athletes to attend the Olympic Games in Sochi next year.

Rights advocates have called for a boycott of the Sochi Games to protest Russia's new laws targeting gays and other sexual minorities, as well as the Kremlin's poor overall record on human rights.